Well after 2 months of running like crap(I drove it like 15 miles in two months ) and trying to figure out what the problem was I took her to the mechanic. The computer is out. The dealer is closed so the mechanic couldnt see if it was the Prom or the actual computer. I should find out tomorrow what the actual problem and how much it will cost.
Now the question.
Computers, do they just go out one day or gradually? The car was running perfect then one day it went to crap.

Thanks
Brian

 

I thought someone once said, that the computers rarely go bad. Were you throwin any codes?

 

the mechanic said that it was throwing like 15-20 codes, all of which ment that the computer was out. I dunno. Auto Zone said that no codes were being put out, he said that they had to try to communicate with the computer several times before the could get anywhere.

Brian

 

There is a difference between scanning for error codes in the Field Service Mode and requesting a serial data diagnostic link with the ECM. The serial link provides real-time data from the ECM and can identify transient errors, incorrect sensor feedback, and a host of other issues that a simple code scan cannot reveal. AutoZone likely only scanned for error codes.

If the mechanic's test was done correctly, and sound diagnostic procedure was used, you may have a failing ECM. That doesn't happen very often, but it CAN happen. More often than not, people blame the ECM for undiagnosed problems and replace them unneccessarily without performing the diagnosis.

Another thing to be aware of is that many link tools don't communicate well, and indeed may require several attempts to establish a serial link. The difficulty in establishing a link may be as much in the test equipment as in the ECM.

You are certainly within your rights to ask how they tried to communicate and what they discovered. It's your car, your hardware, and your money. You are paying THEM to work for YOU, and if they are reputable, they will have no problem in explaining exactly what they did and determined from their diagnosis. They can probably even produce a printed report or sample data string.

Of course, they should also be able to tell you that they eliminated the possibilities of poor connections, poor grounds, and checked the MEMCAL and firmware PROMS in their sockets to eliminate potential thermal creep.

 

When I got my 85 SC the ECM was toast, it caused the Check Engine light to be always on when ever the ignition was in run. The Snap On scanner that was used to diagnose it couldnt detect ANY data at all from the ECM, threw a junkyard ECM in it and all was well...that is until I found out the junk ECM came from a stick and the chip wasnt programmed to lock up the TC

ECM's can go bad, the car will run without it, just runs like sh*t. If its got data its not dead, but it may be sick.

 

I have about 4859372 check engine codes coming up...probably has something to do with the 283635 sensors not hooked up

we dont need no stinking computer :lala:

 

He did say that they took out the prom and put it back and the problem would go away for about 5 seconds then back to the crappy way of running. He works on mostly european cars, my dad will only take his BMW to him and all the other mechanics in town are crap. he said that he was doing everything by the gm book and the next step was to test the prom then the computer and replace both if needed. If I need to replace one or both what kind of cost am I looking at? he said that the last computer he replaced was around $90. But I should find out more today.

Thanks for all the help,
Brian

 

Last time I bought an ECM it was about 65 bucks, chips were around 125 bucks...but this is the dogbrain, retard computer that came in 85's the more advanced ECM in the 89 may be a bit more money, call your local parts stores and GM dealer...I believe you can buy the ECM's reconditioned or new from most parts chains, but the chips are a dealer only item, also check gmpartsdirect.com

 

Well Ray, the mechanic, called and said that the chip would be $70 and the ecm is $280. He also said that he thinks it is the ecm because when he taps on it the SES light goes off, and then he taps it again and it goes on, but the whole time the car still runs like crap. He checked all of the connections and grounds and they are all good. I told him to get the ecm and we will see. He should have it by this afternoon and I will find out by the end of the day if I need to get a new chip also.
Monkey, I checked gmparts and they didnt have anything for my ecm, thanks though, I forgot about that site.
Brian

 

the ecm p/n is 1227165 that is for the 86-89 ECM...Autozone carries it for 80.99 plus 140 bucks core charge. I've used the A-1 brand ECM they sell with no troubles.

 

I had an ecm go out on me before. I hooked it up to a snap-on scanner and saw that all the data from the sensors was going haywire. It was a sudden thing for me. It would run fine and then all of the sudden it would start going nuts. A Napa ECM fixed my problem.

 

I called the mechanic and he said that he didnt deal with autozone and A-1 ecm because of too many bad experiences. When I asked if I could grab one he kind of bitched out and said he couldnt guarante the work and he didnt appreciate people second guessing him like that, "the non-refurbished ac delco is what gm uses so that is what I use" I think he is just too used of people like my dad that go in there and hand him a bag of money and dont question anything he says. I wont deal with him again unless it is something so serious I cant take care of it. This hole thing is gonna cost me about $500. man I would have loved to have spent $500 on so many other things for my car.

Brian

 

Not to argue with those who don't like to be second-guessed, but GM DOES recondition ECMs. I have two of them, and they even come with a different part number. They are still gauranteed, however.

Incidentally, a NEW genuine GM EPROM for your car is $53.00, but I'm not arguing, nor second-guessing.

 

At this point I am just so sick of not being able to drive my car that I just want to get it fixed. From now on I will get things checked out, and only checked out by a mechanic and then I will have to check on here. I just assumed that the guy would try and find the best prices. Like I said before, he is just used of money bags that dont talk back. Kind of sucks but that is what I get for letting my dad talk me into his mechanic.

Thanks for all the help,
Brian

 

I take it by your tone that you already paid for this?????

Too bad if you did.... I have the 165 ECM and two EEPROM equipped MAF Memcals from my GTA for sale (recently swapped to Speed Density)..... Could have gotten by pretty cheap! But I still have to wonder about the ECM just up and dying like that.

I'll also second what Vader said. All of the GM ECM/PCMs that I bought/installed in my days as a tech were/are reconditioned ones and carry a new p/n.

 

If you analyze it a bit, you really aren't getting "shafted". Most reputable repair centers won't risk using questionable parts. Your technician is simply covering his/her butt by using the BEST parts available, so there are no concerns over warranty repairs and leaving you stranded somewhere between "Nowhere's-ville" and "Timbuck-Three". There's nothing wrong with the selection of the NEW ECM for your car, except that a repair center with customer satisfaction in mind would generally contact the vehicle owner with a prognosis and options BEFORE finishing repairs. If you didn't have that understanding with the tech before the job started, you should remember to do that next time. As I recall, you DID tell him to get the ECM, after all.

On the up-side, it sounds as if the analysis was done correctly and with reasonable prudence. At least the troubleshooting guide was followed instead of the more common reflex of just slamming in a new ECM when there is an intermittent problem. There are a lot of ECMs replaced unneccessarily, but your's may have be a rare, genuine problem with the ECM.

And for more positive thoughts, your car should be running more reliably now, so you really didn't waste your money. The money you should save in fuel and frustration should eventually offset the repair costs - and you've got your car back.

 

Well after the mechanic ordering the ecm, not getting it til a day later, having the ecm arrive busted, order another, I HAVE MY CAR!!!
I think there was something wrong with it the whole time I had it cause the car is alot stronger now. I need to take it to the "local track" and see if there is an improvement of my 96mph 1/4 mile.

Thanks for all the help,

Brian

 

If you got a new Memcal, it likely has the most updated form of the PROM available from GM on it and may have a better tune, thus make more power. Congrats on getting it running again, but be sure to look for a deal next time and do it yourself, no better feeling than fixing your own car and saving a buck .... or ten .

 

...or $406.13

Thanks, I think that it has the same tune but more power. I cant really tell though, it has been so long since I heard my baby purr.
I am gonna go race my buddies 98 Z28 tomorrow and see if I gained any ground on him.

Brian